Tubular writing pen

ABSTRACT

A tubular writing instrument having a writing nib consisting of a cylindrical body having an inside bore operatively containing a drop weight and cleaning wire extending therefrom which projects into a writing tube positioned in the front of the writing nib, the inside bore being connected with a compensating chamber for the ink through an aperture interconnecting the compensating chamber and the bore through the body of the cylindrical body.

United States Patent 11 1 Glasa et al. 1 1 Sept. 4,1973

[ TUBULAR WRITING PEN 3,418,058 12/1968 GOSSel 401 259 3,442,597 5/1969 Hebbom et al... 401/259 [75] lnvenmrs' Stefan G135, wedel, Werner 3,539,2 9 11/1970 Dahle 401/259 Westphal, Pinneberg, both of Germany Assignee: Koh-l-Noor Rapidograph, Inc.,

Bloomsbury, NJ.

Filed: Aug. 29, 1972 Appl. No.: 284,537

Foreign Application Priority Data Dec. 1, 1971 Germany P 21 59 522.2

U.S. Cl. 401/259 Int. Cl. B43k l/06 Field of Search ..40l/258-260 References Cited UNITED STATES PATENTS 10/1940 Wallace 401/259 Primary Examiner-Lawrence Charles Att0rneyDavid I-l. Semmes 9 Claims, 2 Drawing-Figures PATENTEDSEP. 4191s l 2 3 411 r 4 z bl FIG. 1

TUBULAR WRITING PEN BACKGROUND OF THE INVENTION In known tubular writing instruments or stylographic pens, a compensating chamber for india ink or the like is normally cut in as a zigzag passage on the outside of the cylindrical body of the writing nib and, with the exception of an outlet opening to the outside air, is covered by a removable closing element. While this arrangement serves, at least in part, to avoid difficulties resulting from a screwing in of the cylindrical body into a mounting support, the body having the compensating chamber on the outside surface, such difficulties arising through settling of dried india ink in the area of the thread and thus the difficulties during uncovering of the compensating chamber for the india'ink for cleaning purposes, but for production of such writing instruments relatively complicated molds are needed and, particularly the closing element, must be attached in an air tight manner.

SUMMARY OF THE INVENTION The writing nib 12 is provided with an annular groove 22 extending rearwardly therein and terminating in a sealing shoulder 24. The annular groove opens at its front end 26 and has an annular shoulder at 28. The annular groove is connected in its rear with inside bore 14 by means of aperture 30 which, as shown, has frustum shaped or defining limiting surfaces. A central body portion 32 of writing nib 12 extends beyond the groove and annular shoulder 28 and the external surface thereof, in the embodiment shown, is in the shape of a frustated cone and defines an inside limiting surface for compensating chamber 34 to be defined hereinafter.

- The interior surface of groove 22 opposed to the sur- The writing nib holding the writing tube consists of 35 'shaped passage or indentation is likewise adapted'for the injection molding process.

Additional objects, features and advantages of the present invention will be more readily apparent from the following detailed description of an embodiment thereof when taken together with the accompanying drawings in which:

FIG. 1 is an elevational view, parts being broken away, and partly in section of a tubular writing instrument in accordance with the invention; and

FIG. 2 is an exploded view of the tubular writing in strument in accordance with FIG, 1.

Referring now in greater detail to the drawings, there is shown, in part, a tubular writing instrument generally designated 10, which includes a writing nib l2 consisting of a cylindrical body having abore l4therein and a writing tube or point 16 inserted in the front end thereof. The bore 14 is adapted to operatively accommodate drop weight 18 having a cleaningwire 20 af- 1 fixed thereto and which, in a normal manner, operatively extends into and through tube 16 for the purpose of cleaning dried ink out of the interior of tube 16.

The bore and drop weight, as shown inthe drawings, are frustoconical in shape, but could be cylindrical. A cartridge with ink is, as normal, placed on the rear end of the writing nib and a supporting shaft can be attached directly at this end, which then includes a supply chamber for the ink.

face of central body portion 32 is also preferably conical shaped or disposed so that the groove is in the form of a truncated cone, although the groove could otherwise be cylindrical with respect to one or both of its interior surfaces.

An annular body generally designated 36 is formed on an elastic material such as, for example, polyethylene, and preferably of a more elastic material than that constituting the body of the writing nib. The rearward portion of annular body 36 is preferably of truncated conical shape for mating with the interior of anular groove 22 in a friction fit therein, the mating surfaces in any event being similarly configured for the friction mating engagement. The annular body terminates in a shaped shoulder portion 38 for sealing engagement with sealing shoulder 24 as shown in FIG. 1.

The annular body is also provided with an outwardly extended annular shoulder 40 for operative limiting engagement with annular-shoulder 28 on writing nib 12. The inner surface of annular body 36 is provided with a spiral shaped depression or groove 42 which opens into aperture 30 and, in conjunction with the external surface of central body portion 32,-comprises compensating chamber 34. Since the annular body consists of elastic material, it adapts itself tightly to the shape of the annular groove so that there is a connection between the inside bore andthe surrounding air only by way of the spiral shaped depressions or grooves. If the annular body is to be removed for cleaning purposes, the friction fit facilitates removal. The coacting surfaces of the annular groove and the annular body, whether of a frustum shape or cylindrical, provide the necessary seal. In the shown embodiment, the inside surface of the annular groove has -a frustum shape, while the outside limiting surface is essentially cylindrical but can also have an oppositely frustum shaped inclination.

In the front part of the inside limiting surface formed by the surface of central body portion 32 is a thread 44 having the same pitch and shaped as-the spiral shaped depression or groove 42. The bridges or threads running betweenthe individual passages of the grooves '42 in this-region are raised at 46 or are of greater depth than the remainder so that they can be screwed intothe thread 44. It will be apparent that by this screw thread mating there will be prevented on the one hand an axial shifting of the angular body 36, while on the other hand it can be removed from the annular groove very simply without any additional tool byunscrewing the raised theads 46 from the thread 44, whereby the inside frusturn shaped surface of body 36 is quickly released from the inside limiting surface of body portion 32 after a shortturn, so that a simple removal of the annular body for purposes of cleaning or replacement is possible.

The thread 44 does not completely close the spiral shaped chamber in the front part of annular body 34 due to the provision of a free or open area at 48, so that a connection exists from the compensating chamber for the ink to the surrounding air.

Easy removal of annular body 34 is facilitated by a gripping area formed by serrations or the like. Insertion and removal, accordingly, for reasons pointed out above, involve simple and easy operations and the interaction of the various sealing shoulders provide a tight fit.

The tubular writing instrument as shown can be easily provided with a color or coding ring and with a locking mechanism for the drop weight. To this end, a ring 52 with a molded in thread 54 and a lock mechanism 56 are produced in a single piece interconnected with one another by means of a predetermined breaking point. This element, as shown in FIG. 2, is pressed from the rear onto the cylindrical portion 58 of writing nib 12 for mounting. At the same time, the ring 52 and locking mechanism 56 are separated, the locking mechanism being clamped down firmly in the inside bore, the ring 52 then being pressed downward and moved by annular shoulder 60, so that the shoulder will hold it firmly in the position shown in FIG. 1. Additionally, some device to prevent twisting, now shown, can consist, for example, of a peg provided on the lower surface of ring 52 and which peg would project into a corresponding bore in the body of cylindrical portion 58 so that the ring cannot be twisted whena holding shaft, for example, is screwed on winding or threads 54.

It will be recognized from FIG. 2 of the drawings that the tubular writing instrument, according to the present invention, consists of a small number of very simply constructed elements whereby the annular body 36, the writing nib l2 and the element constituting the ring 52 and the locking mechanism 56 for the drop weight can be produced very simply by injection molding. As a result of this construction, it is possible to supply a user with replaceable annular bodies which-can be used as replacements for bodies contaminated to a substantial extent by deposits of ink. I

It is also pointed out that aperture 30 connecting the inside bore with the compensating chamber for the ink is formed such that its rear wall, in relation to the longitudinal axis of the tubular writing instrument, slants to the rear from the outside toward the inside. As a result, an injection mold with a wedge that can be swiveled out for the production of aperture 30 can be used for the manufacture of the cylindrical body or writing nib l2 and no additional processing of the cylindrical body is required.

If desired, a larger compensating chamber for the india ink can be obtained by providing spiral shaped grooves or depressions on both the cylindrical or frustum shaped surfaces of the annular body. It is also contemplated that the depth of the thread on the inside limiting surface can decrease continously from front to rear and, with such construction, the annular body can be easily screwed into the annular groove and again unscrewed, since even after a few turns the entire frustum shaped surface of the annular body has come off the inner limiting surface of the annular groove and can be pulled out of it.

Manifestly, minor changes in details of construction can be effected without departing from the spirit and scope of the invention as defined in and limited solely by the appended claims.

We claim:

1. A tubular writing instrument comprising:

A. a nib including:

i. a generally cylindrical body having a bore therein;

ii. a writing tube in the front end; and

iii. a drop weight and cleaning wire operatively mounted in said bore;

B. an ink chamber mounted on the end of said nib communicating with said bore;

C. a forwardly open annular groove in said cylindrical body;

D. an aperture interconnecting the inner end of said annular groove and said bore;

E. a resilient annular body in said bore in sealing engagement therewith; and

F. a spiral shaped groove on the inner surface of said annular body, said spiral shaped groove coacting with a surface of said annular groove to form a spiral shaped compensating chamber connecting at its inner end with said aperture and open at its outer end to the exterior.

2. A tubular writing instrument as claimed in claim 1, said annular groove being frustoconical in configuration,and said annular body having a mating configuration.

3. A tubular writing instrument as claimed in claim 1, wherein a spiral shaped groove is provided additionally on the surface of said annular groove mating with said spiral shaped groove on the inner surface of said annular body.

4. A tubular writing instrument as claimed in claim 2, wherein a spiral shaped groove is provided additionally on the surface of said annular groove mating with said spiral shaped groove on the inner surface of said annular body.

5. A tubular writing instrument as claimed in claim 3, said groove in said annular groove being provided in the forward end thereof and decreasing in depth from the front to the rear, ridges formed between the grooves interconnecting and coacting to form a sealing engagement of said resilient annular body in said annular groove in said cylindrical body.

6. A tubular writing instrument as claimed in claim 5, said cylindrical body having a leading edge axially rearwardly displaced from the front end thereof, said annular body having an annular shoulder rearwardly displaced from the front end thereof fitting against said leading edge and being outwardly pointed.

7. A tubular writing instrument as claimed in claim 6, wherein the rear wall of said aperture is rearwardly slanted from the outside to the inside thereof.

8. A tubular writing instrument as claimed in claim 7, including a ring press fitted on the rear end of said cylindrical body and having a locking mechanism for said drop weight connected thereto by a frangible'connector and adapted to be pressed in the rear of said cylindrical body upon mounting thereon.

9. A tubular writing instrument as claimed in claim 8, said ring including an attaching thread thereon adapted for interconnection with a supporting shaft and an ink supply chamber. 

1. A tubular writing instrument comprising: A. a nib including: i. a generally cylindrical body having a bore therein; ii. a writing tube in the front end; and iii. a drop weight and cleaning wire operatively mounted in said bore; B. an ink chamber mounted on the end of said nib communicating with said bore; C. a forwardly open annular groove in said cylindrical body; D. an aperture interconnecting the inner end of said annular groove and said bore; E. a resilient annular body in said bore in sealing engagement therewith; and F. a spiral shaped groove on the inner surface of said annular body, said spiral shaped groove coacting with a surface of said annular groove to form a spiral shaped compensating chamber connecting at its iNner end with said aperture and open at its outer end to the exterior.
 2. A tubular writing instrument as claimed in claim 1, said annular groove being frustoconical in configuration,and said annular body having a mating configuration.
 3. A tubular writing instrument as claimed in claim 1, wherein a spiral shaped groove is provided additionally on the surface of said annular groove mating with said spiral shaped groove on the inner surface of said annular body.
 4. A tubular writing instrument as claimed in claim 2, wherein a spiral shaped groove is provided additionally on the surface of said annular groove mating with said spiral shaped groove on the inner surface of said annular body.
 5. A tubular writing instrument as claimed in claim 3, said groove in said annular groove being provided in the forward end thereof and decreasing in depth from the front to the rear, ridges formed between the grooves interconnecting and coacting to form a sealing engagement of said resilient annular body in said annular groove in said cylindrical body.
 6. A tubular writing instrument as claimed in claim 5, said cylindrical body having a leading edge axially rearwardly displaced from the front end thereof, said annular body having an annular shoulder rearwardly displaced from the front end thereof fitting against said leading edge and being outwardly pointed.
 7. A tubular writing instrument as claimed in claim 6, wherein the rear wall of said aperture is rearwardly slanted from the outside to the inside thereof.
 8. A tubular writing instrument as claimed in claim 7, including a ring press fitted on the rear end of said cylindrical body and having a locking mechanism for said drop weight connected thereto by a frangible connector and adapted to be pressed in the rear of said cylindrical body upon mounting thereon.
 9. A tubular writing instrument as claimed in claim 8, said ring including an attaching thread thereon adapted for interconnection with a supporting shaft and an ink supply chamber. 